Concrete Calculator
Calculate the volume of concrete for a slab from its length, width and depth.
Concrete volume0.900m³
With 10% waste allowance0.990m³
In cubic yards1.177yd³
Concrete volume = length × width × depth, all in metres. A 3 m × 3 m slab at 0.1 m (10 cm) thick is 3 × 3 × 0.1 = 0.9 m³. Add about 10% for spillage, uneven ground and over-excavation, giving ≈ 0.99 m³. One cubic metre ≈ 1.308 cubic yards if you order in imperial units.
Questions
How do I calculate concrete volume?
Multiply length × width × depth in metres. A 3 m by 3 m slab 0.1 m thick needs 3 × 3 × 0.1 = 0.9 cubic metres of concrete.
How much extra should I order?
Add roughly 10% to cover spillage, uneven subgrade and waste. For a 0.9 m³ slab that means ordering about 1 m³.